Customer wants a lush new back yd. The grass that is there is very thin not doing great. It's mostly shaded and last fall the wet leaves piled up and sat for weeks. He brought in 5 yds top soil and covered up old grass and reseeded. Last week a lot of the old grass pushed thur with a lot of the seed growing in, looks funky and a lot of dirt. He left a message asking for the old grass cut out and new sod brought in. The old grass is very thin. The sod cutter will not do its job correctly cause there's no good grass. Can I rototill rake and sod? Will leaving the grass there rototilled over and sod on top be alright? Thx fellas. Be safe out there.